Paramagnetic Defects Induced in Naphthalene and Anthracene Single Crystals by Neutron Irradiation at Low Temperature

Abstract

Radiation induced defects in naphthalene and anthracene single crystals irradiated with reactor neutron at 10°∼17°K were studied by ESR at 4.2°K, 77°K, and room temperature.
Initial radicals produced in naphthalene at low temperature have been identified to be α-naphthyl radical and isolated hydrogen atoms, whereas in anthracene 9-anthryl radical and isolated hydrogen atoms have been detected. At room temperature the ESR signals of these radicals disappear, and α-hydronaphthyl radicals and dibenzo-cyclohexadienyl radicals have been detected innaphthalene and anthrance, respectively. The results indicate the following processes in the radiation damage in naphthalene and anthracene: RH+Reactor Neutron→R^·+H^·, RH+H^·→RH^·₂.